A senior Chinese envoy, Vice Foreign Minister Dai Bingguo, met top Bush administration officials in Washington Friday on Beijing's efforts to convene further talks on North Korea's nuclear program. The two sides agreed to continue pursuing a diplomatic solution, but there was no immediate announcement of a new round of talks with Pyongyang.

The Chinese envoy, who ended a four-day visit to North Korea earlier in the week, met Vice President Dick Cheney and National Security Adviser Condoleezza Rice at the White House, then came here for an unusually long two-and-a-half hour meeting with Secretary Colin Powell.

Only Mr. Dai spoke to reporters, calling his Washington talks "useful" and saying that China and the United States agreed on the need to work together to push the process forward, and solve the problem of North Korea's nuclear program through dialogue.

A State Department spokesman Richard Boucher said Secretary Powell expressed appreciation for the "tremendous" effort that China has put into the effort to resolve the crisis.

He said Mr. Powell noted to Mr. Dai that President Bush has consistently pursued a diplomatic approach, despite what the spokesman said were North Korean "threats and steps in the wrong direction."

Much of the discussion is understood to have focussed on the format for new talks on the North Korean nuclear weapons program.

China hosted three-way meeting with the United States and North Korea in April and is reported to be ready to hold another.

The Bush administration has not ruled out a return to a trilateral format, but has pressed for South Korea and Japan to take part as well.

In his statement on the meeting, spokesman Boucher said the United States made clear to Mr. Dai its "strong belief" that the time has come for other parties to join the multi-lateral talks in order to ensure that all key issues are addressed.

The Bush administration has rejected North Korea's demand for one-on-one talks. U.S. officials insist the issue is a matter of regional concern, and do not want to be seen as rewarding Pyongyang for, in their view, precipitating the crisis by violating nuclear agreements.

The New York Times reported Friday that China was urging both sides to resolve the impasse by reviving their 1994 "Joint Framework" that froze the North Korean nuclear program in exchange for western fuel aid and the promise of two safeguarded nuclear power plants.

However, at a news briefing, spokesman Boucher said the United States is not interested in resurrecting the deal, which he said was scuttled by North Korea and, in any case, does not permanently end its nuclear program.

"I don't know that that's actually a live issue at this point," he said. "The North Koreans said it was effectively nullified, if I remember correctly. But in any case the North Koreans were the ones that violated. They were the ones that breached it, after agreeing not to develop nuclear weapons programs, went off and started a different program to enrich uranium. The Secretary said, if we're going to resolve this in a matter that we want, that the Chinese want, that the international community wants, and that's an irreversible and verifiable end their nuclear weapons programs, there are going to have to be different arrangements in the future."

A Chinese spokesman said earlier this week the "Agreed Framework" had successfully capped North Korea's nuclear program for a decade and should remain the basis for negotiations.

After the United States confronted North Korea with evidence it was secretly enriching uranium in violation of the framework last year, Pyongyang restarted a nuclear reactor frozen under the accord, and pulled out of the Nuclear Non-Proliferation Treaty.

U.S. officials say North Korean diplomats told them last week that Pyongyang had reprocessed thousands of spent fuel rods at the reactor complex, which if true would provide enough plutonium to build several nuclear weapons in addition to the one or two that North Korea is long believed to possess.